Table 2 Parameterization of the target parameters. ZWD stands for zenith wet delay, and GRN/GRE for north and east gradients. STACLK is the station clock, and STAX are the station positions. Finally the EOP are presented in the form of dX/dY as the celestial pole offsets, and x\(_{p}\)/y\(_{p}\) as polar motion in X and Y. The VA-ICRF3 is produced with solution A2 in a process presented in the section Radio source positions in VGOS
From: Evaluation of the first three years of Vgos 24 h sessions using a Kalman filter with C5++
Parameter | Parameter type | Stochastic noise | ||
|---|---|---|---|---|
S1 | S2 | S3 | ||
ZWD | Random walk | 36 mm\(^2\)/h | ||
GRN/GRE | Random walk | 0.36 mm\(^2\)/h | ||
STACLK | Integrated random walk | 0.64 ns\(^2\)/day\(^3\) | ||
STAX | Constant | – | ||
UT1-UTC | Constant | – | ||
dX/dY | Constant or random walk | – | – | 0.00011 mas\(^{2}\)/day |
x\(_{p}\)/y\(_{p}\) | Constant or random walk | – | – | 0.0025 mas\(^{2}\)/day |
A priori TRF | ITRF2020 | |||
A priori CRF | ICRF3 | VA-ICRF3 | VA-ICRF3 | |
A priori EOP | IERS-20-C04 | |||
Weighting technique | Baseline-based VCE | |||